harvey



- (NoModeL) SCREW SWAGING MACHINE.

- v 2 Sheets-heet 2. H. A. HARVEY;

Patented Nov. 3, 1885.

UNITED STATES PATENT QFFICE.

HAYWARD A. HARVEY, or ORANGE, NEW JERSEY.

,SCREW-SWAGING MACHINE.

SPECIFICATION forming part of Letters Patent No. 329,737, dated November3, 1885.

Application filed June 8, 1885. Serial No. 167,948. (No model.)

To aZZ whom it may concern:

Be it known that I, HAYWARD A. HARVEY, of Orange, in the county of Essexand State of New Jersey, have invented a new Improvement in Machines forRolling the Threads of Screws; and ldo hereby declare the following,

whentaken-in connection with accompanying drawings and the letters ofreference marked Fig. 3, an elevation of the feeding mechanism, seen atthe upper right hand in Fig. 2; Fig, '4, a vertical section through linea: a: of Fig. 3;,

Fig. 5, a top View, upon a larger scale, of the feed mechanism, showingthe blank fed from the upper end of the ways, and standing in front ofthe delivery-slide; Fig. 6, a similar view showing the delivery-slide inthe act of pushinga blank toward the rotating die; Fig. 7, an elevation,upon a larger scale, of the parts shown in Fig. 3; Fig. 8, a verticalsection taken through line y y of Fig. 5; Fig. 9, a transverse sectionthrough the dies, showing a screw in place as finished, on an enlargedscale.

This invention relates to an improvement in that class of machines forthreading screws in which the blank is caused to roll between diespresenting corresponding surfaces, the said surfaces having parallelridges formed thereon at the proper angle of inclination with the planeof motion of the dies, and whereby the said ridges impress the surfaceof the blank rolled between them, and so as to form a correspondingspiral rib on the blank, and particularly to that class of machines forrolling threads which are constructed to continue the rib on the blankfrom the body down onto a tapered or conical point, and so as to formwhat are commonly called gimlet-pointed screws.

Previous to my present invention the dies between which the blanks wererolled to form the spiral rib or thread thereon were constructed withtheir surfaces parallel to the extent of the cylindrical portion of thebody of thescrew to be formed, and at the termination of that portion ofthe surface the faces of the two dies converged to substantially acentral point'between the dies, the ridges on the dies being continuedover the converging portions to form the gimlet-point, and so that thesurfaces of both dies'worked alike upon the pointed portion of thescrew, each servingas a rest or resistance for the other. Such a machineis the subject of my application for patent, Serial No. 90,261.

While I have attained good results in the machine constructed as setforth in my said application, Ihave at times experienced difficulties,from the'tendency of the blank to work longitudinally between the diesunder the action of the gimlet-pointing portion, such movementmitheblanktending tOstllQDlj,

of the body.

The object of my present invention is principally to avoid thisdifficulty, as well as to materially simplify the machine; and theinvention consists in constructing one of the dies with its facesubstantially parallel throughout with the axis of the blank tobethreaded, the

destroy the thread on'the cylindrical ortion companion die having itssurface substantially parallel to the said axis, and to the face of thefirst-mentioned die, to an extent equal to the length of the cylindricalportion of the blank to be threaded, thence inclined toward the saidaxis and face of the other die, the facesv of the two dies beingconstructed with,parallel ridges at the proper angle of inclination withthe plane of motion of the dies, the ridges on the one die continuedfrom its parallel surface onto. the inclined portion, and whereby, asthe blank is rolled between the said two dies, its surface will beimpressed by the said ridges, and a corresponding spiral rib raised onthe body of the blank, continued from the body down to the point by theinclined portion of the one die, and as more fully hereinafterdescribed.

In illustrating my invention I show it in a machine having one revolvingdie, the pe-. riphcry of which is constructed with inclined ridges,combined with a corresponding segment-shapeddie, fixed with relation tothe revolving die, and its adjacent surface having corresponding ridges,so that the blank will.

be rolled between the two, and with its axis parallel to the axis of therevolving die, and

in such revolution its surface. will receive the impression of theridges on the dies, so as to form a corresponding spiral rib on the bodyof the blank,- this machine being substantially the same construction asthat shown in Pat- .ent No. 306,132, granted to O. S. Clark and 'inginto a corresponding gear, D, onthe drivingshaft, but may be otherwiseapplied. E is the. die stock or head, which is fixed to the shaft, andso'as to present a surface concentric therewith. -.Upon this stock aring-shaped die, F, is fixed, the depth ==of which corresponds to thecylindrical portion of the body of the screw to be threaded. "This ringpresents a periphery substantially parallel with the axis of'the shaft.Immediately below the ring is a second ring, G, which at its junctionwith the ring F is of the same diameter as the ring F, but graduallyincreasing in diameter therefrom. The thickness of the ring G issubstantially that of the length of the pointed portion .of the screw,and its increasing diameter is equal to substantially one-half,thediameter of thescrew to be rolled.

The face or peripheryof the rings F ,G is

constructed with parallel ridges at the proper angle of inclination withthe plane of motion of the rings, the rings being firmly secured to ,thehead, and so as to revolve therewith, as

' here represented. The path of revolution is in a horizontal plane.Adjacent to the face of the revolving diesone or more segments, H, arearranged, the face of which is substant-ially parallel with the axis ofrevolution of the ring-shaped dies F G. The depth or width of the faceof the segment-shaped dies is immaterial, only that it should be atleast equal to the length of the cylindrical portion of the screw to bethreaded. The segments H are constructed with inclined ridgescorresponding to those on the revolving cylindrical die, and so that ablank introduced at the proper point-say at one end of thesegment-will'be rolled along the surface of the segment, between thatsurface and the surface of the revolving die, and the-surface of thebody of the blank will be impressed by the ridges, so

-as to form a spiral rib on the body of the blank, as indicated-in Fig.9, where the blank is shown as having the thread completely formed. Theformation of the thread by the revolving dies is progressive from itsco1nlnencement at one end of the segment until it is discharged fullyformed at the opposite end.

In illustrating my invention I show feeding devices substantially thesame as shown in the saidPatcnt No. 306,132, which are designed tosuccessively deliver blanks between the dies at the proper time,so thatthe blanks die and rolled along between the revolving and stationarydies and delivered. from the machine. a The illustration ofthe feedingdevice does not require description in-this-application, as itconstitutes no part of my present invention. Any of the feeding devices-in numerous patents heretofore granted to me for this class of machinesmay .be'employed. I

"The blanks preparatory to being pointed, as indicated iniig." *8," and,being properly delivered to the feeding device, are I I) deliveredsuccessively to .the dies, as seen in-l Figsp5, 6,,and8. As the. blankpassesbe tween the revolving and stationary dies the ridges on thei'aceof the two dies firmly grasp and supporttheblank while being rolled. At

the. same time the single ridgeson the inclined rolledare pQrtion of,the one .die operate upon the pointed portion of the blank, so as tocontinnethe rib .nuthe. blank from the cylindrical portion downonto'thepoint, as seen in'Fig. 9. As the.

pointed portion is not grasped between op posing surfaces, the tendencytoraise the blank under the action or formation of, the rib on the pointis avoided. The parallel portion of the die firmly supports the blankagainst. the

action of the single inclined portion, and so thatthe point, whateveritsinclination, will be concentric throughout.

Anothergreatadvantage of this improve- 'ment.arises from the fact thatone die having its surface. parallel with the axis throughout maybe madeof a depth ,sufiicient for the. longest screw to be threaded, andthereby serveflfor all lengths of screws having that particular pitch ofthread. In all screws having the same pitch of thread the point is thesame; hence the same ring-shaped die G will serve for all lengths ofscrews, it only being necessary then to supply the cylindricalringshaped die F for the depths corresponding to the varying lengths ofscrews, so that bysimply changing the cylindrical ring F and adjustingthe pointingring G the same stationary segment-die and the same ringwill serve -for all lengths of screws of the same pitch. The two rings FG, however, may be made as one, if preferred, and the segment may bemade of a depth only corresponding to the length of the cylindricalportion of the blank to be threaded; but by constructing the rings intwo parts and the. segment of maximum I'have represented the fixed orsegmentof the cylindrical portion of the blank to be threaded, and theremainder of its face inclined corresponding to the point to be formed;but this arrangement may be reversed and the revolving die becylindrically ridged and the segment have the pointing portion of itsface inclined toward the moving die.

While I prefer to'perform the rolling operation by means of acylindrical die combined with a segment-shaped die, the face of one ofwhich is substantially parallel throughout with the axis of the blank tobe rolled, and the other parallel with the said axis to a depth equal tothe length of the cylindrical portion of the body of the blank to berolled, thence gradually inclined toward the opposite die to the depthof the pointed portion of the blank, the said inclination beingsubstantially equal to one-half the diameter of the point, the dies maybe straight, one or both receiving a reciprocating motion, as inwell-known machines for rolling screws.

1. In a machine for rolling threads on screws, the dies between whichthe blank is rolled having parallel ridges formed thereon at the properangle of inclination with the plane of motion of the dies, the face ofone of the dies parallel throughout with .the axis of A the blank to berolled, the face of the cone 3 5 sponding die also substantiallyparallel with the said axis to an extent equal to the cylindricalportion of the blank to be threaded, thence-inclined toward the oppositedie, the depth of the'said inclination being substantially equal to thelength of the pointed portion of the blank, and the inclinationsubstantially equal to one-half the diameter of the blank, substantiallyas described.

2.. In a machine for rolling threads on screws, a rotating die and astationary curved die, in which the working-faces for impressing thethreads upon the body of the blank present parallel ridges at the properangle of inclination with the plane of motion of the rotating die, theface of one die substantially parallel throughout with the axis ofrotation, the face of the other die parallel with the axis of rotationto a depth substantially equal to the threaded portion of the screw tobe produced, thence gradually inclined toward the opposite die, thedepth of the inclined por-- tion being substantially equal to thepointed portion of the screw to be produced, and the inclinationsubstantially equal to one half the diameter of the blank, substantiallyas described.

HAYWARD A. HARVEY. Witnessesz' 'JOHN' E. EARLE, FRED G. EARLE.

